Microsoft's Windows Update Service is working it's way through it's stabalising phase. Beta 2 was out last November, an RC is due in the next few months, and RTM planned late this half (ie by the end of June). One issue that's been noted with the prodcut is the name. WUS simply is a bad name (aside from the sound of the name when spoken sounding sub-optminal and highly mockable) because it's not a Windows Update Service. It's a Software Update service, initially updating Windows, Office, SQL, Exchange. It also does more than just update software - since in theory at lests, updates to DDKs/SDKs etc could ge shipped vis WUS.
With WUS (or whatever it's called) being a key security product in the small to medium business sector for the coming few years, it's important to get the name right. Every product should pass the Ronseal test: it should do what it says on the tin. By comparion SBS passes this test with flying colours - it's THE small busines server product - a product for small businesses. WUS, on the other hand, fails.
Whatever the name change, there are some changes coming, providing useful improvements over features in the public beta. I'm looking forward to the RC, and putting the product through it's paces. It's also worth remembereing that the beta is not planned to be upgradeable to RTM (and probably not upgradeable to the RC), something that may deter some small businesses testing the beta.
For more on WUS, see the WUS Wiki: http://wus.editme.com